1. Field of the Invention
The present invention relates to a ceramic composition of matter for an apparatus and method of processing (e.g., etching, chemical or physical vapor deposition, etc.) a substrate in a chamber containing a plasma of a processing gas. More specifically, the present invention provides a ceramic composition of matter which may be used to manufacture process kits and dielectric windows wherethrough processing power passes for etching a semiconductor substrate in a reactor chamber containing a high density plasma of a processing gas. The ceramic composition of matter has a high erosion resistance during etching of a semiconductor substrate to prevent corrosive materials from forming inside the reactor chamber.
2. Description of the Prior Art
The semiconductor industry relies on high throughput, single substrate processing reactors which can be used for a variety of different processes such as thermal chemical vapor depositions (CVD), plasma-enhanced CVD (PECVD), plasma-assisted etching, and deposition topography modification by sputtering. Some processing reactors include processing reactor chambers having a dielectric member (i.e., a dielectric window) wherethrough processing power passes to aid in sustaining a plasma from a processing gas within the reactor chamber for processing a wafer substrate.
Process kits are sometimes employed within the reactor chamber as an aid to processing a wafer substrate.
Process kits typically include a capture ring which is supported by a pedestal assembly for retaining a wafer substrate in a generally stationary position for processing. Process kits also typically include a focus ring which in operation is supported by the capture ring for assisting in confining plasma processing gas over the wafer substrate to optimize the processing of the same.
Dielectric members (e.g., dielectric windows) and process kits are generally constructed of a ceramic material, such as high parity alumina ceramics containing 99.5% by weight or higher aluminum oxide (Al.sub.2 O.sub.3). When high density halogen-containing plasmas contact alumina dielectric members and alumina process kits during etching of wafer substrates, erosion of alumina occurs, causing the formation of large particles and contaminant compounds which can damage patterned wafer substrates.
Therefore, what is needed and what has been invented is an improved ceramic composition of matter from which dielectric members and process kits may be constructed. What is further needed and what has been further invented are dielectric members (i.e., dielectric windows) and process kits which are all highly resistant to erosion during etching of a wafer substrate in a high density plasma of an etchant gas.